Mobile TV Handover Synchronization via Delay Compensation
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Solution Overview
Problem
Existing mobile TV systems face interruptions when switching between DVB-H and WiFi networks due to differences in transmission delays, leading to issues with duplicate and missing content packets during handovers.
Innovation Solution
A method and apparatus for synchronizing video streams by measuring delay differences between DVB-H and WiFi networks, dropping duplicate packets, and requesting missing content using an ARQ mechanism to ensure continuous playback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If handover is performed between DVB-H and WiFi networks, then network coverage and accessibility are improved, but transmission delay differences cause duplicate and missing content packets
Solution Approach 1:
The patent performs preliminary actions by measuring transmission delays from both DVB-H and WiFi networks before handover occurs. The system calculates delay differences in advance and pre-adjusts buffer timing to compensate for expected delay variations, preventing duplicate and missing packets before they occur during handover.
Solution Approach 2:
The system continuously monitors and measures transmission delays from both networks, using this feedback to dynamically adjust buffer timing and handover parameters. This closed-loop feedback mechanism ensures that delay differences are compensated in real-time, maintaining content packet accuracy during network transitions.
2Duration of action of stationary object
If content is buffered during handover, then continuous playback is maintained, but delay measurement and packet management complexity increases
Solution Approach 1:
The patent changes buffer timing parameters dynamically based on measured delay differences between networks. By adjusting buffer delay as a controllable parameter rather than using fixed timing, the system maintains continuous playback while managing complexity through parameterization rather than complex control logic.
3Reliability
If delay difference is measured and compensated, then seamless handover is achieved, but processing overhead and system complexity increase
Solution Approach 1:
The system performs self-service by autonomously measuring its own transmission delays and automatically compensating for delay differences without external intervention. This self-measuring and self-correcting approach achieves seamless handover while minimizing processing overhead by using the system's existing resources for delay measurement rather than adding complex external measurement infrastructure.
Data Source
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AI summary
A method and apparatus are described for content delivery, including receiving content from a first network, moving into a coverage area of a second network, performing a handover, receiving content from the second network and dropping any duplicate content packets. Also described are a method and apparatus for content delivery including receiving content from a first network, performing a handover, receiving content from a second network, determining if any content is missing and requesting the missing content.